Loads on rail cars need to be restrained from shifting under the various loads imposed by draft, buff, and rocking of the car. For particular types of loads, such as large rolls or coils of sheet material, or palletized loads, tensioning mechanisms using straps and anchors are advantageous. A special anchor fitting adapted to receive a corresponding anchor pin combines with a strap length controlling mechanism midway from the ends of a strap to maximize strength, ease of operation, economy in manufacture and minimize damage to rolls, coils or palletized cargo. A simple cam locking mechanism may be used instead of the prior art metal ratchet mechanism on a strap.
The invention was initially adapted to shipment of paper rolls and other rolls of material easily damaged by prior art rail car wall anchors. Other cargoes can be secured to advantage, particularly palletized cargo such as shrink wrapped, packaged juices, or other similarly vulnerable cargo that should be protected from contact with in-car projections during loading, transporting and unloading. Further, appropriately sized snugger straps and hooks could even be used for other materials. In other uses, other transportation devices such as over the road trailers and shipping containers continue to utilize maximum cubic volume (xe2x80x9chigh cubexe2x80x9d) designs for which the ability to recess anchors also has added utility.
The invention combines several distinct elements into an improved cargo snugger strap and hook mechanism. An anchor has an xe2x80x9cLxe2x80x9d shaped aperture which receives a strap pin end, the lower leg of the xe2x80x9cLxe2x80x9d locking the pin in place, the strap bearing on a smoothly curved side wall, the pin being held in place when not under load by a clip member on the back of the anchor and being contained within a pocket in the wall of a railroad box freight car. A strap shortening device enables a two part strap to be shortened to fit the cargo load through the use of a combination of turns and bights around a three part clip having a generally oval ring with an upstanding half oval ring portion displacing the various parts of the strap threaded thereon to increase friction to the point where the strap length can be effectively fixed under load, yet the length varied when not under load.